In recent years, systems called a TV telephone system and a TV conference system have been widespread. For example, in the TV telephone system and the TV conference system, users at remote places can talk to each other by viewing a video image.
For example, in the TV conference system, at two individual mutually distant places, devices for voice conference are provided. The device for voice conference on a sending side collects generated sound from different directions via a plurality of microphones and sends voice signals to the device for voice conference on a partner side. On the other hand, the device for voice conference on a receiving side receives the voice signals collected by the device for voice conference on the partner side and releases the sound from a speaker.
For example, Patent Literature 1 to 3 and Non-Patent Literature 1 propose that the control to obtain more realistic sense is performed in the TV conference system and the TV telephone system.